I'm confused..

[Todd T]

I would like to see where this goes... how does the lowest flowing filter, also make lower EGT's?





hx35 flows 600 cfm at 36psi, hx40 flows 800cfm at 40psi, h2e/hx50 flow 1000cfm at 40psi, hx55 flows 1050 cfm, and hx 60 flows 1600 cfm.



those are a little hard to read, as follows: (left to right)



Stock A/B, stock filter =327CFM@1. 5in. h2o

BHAF=389CFM@1. 5in. h2o

Stock A/B, AFE replacement=407CFM@1. 5in. h2o

K&N "scotty style" RE-0880=583CFM@1. 5in.

h2oAFE 20-40044 (K&N look alike)=620CFM@1. 5in. h2o

AFE magnum 50-10071 (new kit)=820CFM@1. 5in. h2o

 

[moparguy]

I'm a little confused as well.

The chart and flow capacity info looks like the same info Mr. Bob is using in his ad for his aFe system. The filter number he shows as being the equivelant to the BHAF part numbers we'll been using dosen't look right. He shows a Donaldson 145 as the tested filter on his chart, but in the text of his ad, he lists the Donaldson B105006 as being the same as the Napa 2790, Fleetguard 19037,ect. .



Looks like he may not have used the right BHAF in his comparsion. I know mine was a huge improvement over the stock filter with a very modified airbox. And at over 7,000 miles of sometimes very dusty driving on my last oil change, the silicon number on the oil analysis was a 4.



It seems to me that "if" the BHAF dosen't flow as much as some of the others with all the increased filter area it has, then that tells me it's going to provide better filtration, and experiance shows it does that with the necessary airflow to reduce EGTs.



I'll be quite now.



RJR

 

[RustyJC]

Towing our 13,500 lb 5ver, the maximum EGT I see with a BHAF, Edge EZ with boost elbow and 4" exhaust is 1050 degF (down from 1250-1300 degF stock). With our current modification package providing much improved towing power, 10% better fuel economy and no worries at all about EGT's, even if the flow data presented is correct (and I have very serious doubts about that), why do I need more airflow or a lower pressure drop than I'm getting from my BHAF?



Rusty

 

[SlyBones]

First in a post not too long ago where people stated the add was using the wrong MoparGuy filter in the comparison, people posted the correct fleetguard flow ratings. And at 1. 5" of h2o the 390cfm is really close. The 800-900cfm ratings were at a much higher pressure drop. IE 6" or 8" of h2o.



What makes this meaning less for me is that the HX35 flows 600cfm at 36psi, and the stock filter flows 327cfm at 1. 5" of h20 -- But how to you compare h2o to psi ???



This is a static flow rate chart. Seems like we need a chart with curves on it that chart the flow rates at various levels of h2o. And then a way to map that to boost. This way we can see that at 15 psi all filters are adequate, the stock filter fails to keep up at 25psi, the MoparGuy filter keeps up to 35psi, the K&N to 45psi and the new AFE Mag up to 60psi or some kind a thing like this. ( I just made this up for example sake. This does not represent real data )



People could then choose a filter according to their power levels or boost levels.

 

[moparguy]

Right on.

I agree Sly, what's needed is a spread sheet that we could plug in RPM and boost numbers, and prehaps the turbo, then have the cfm numbers show up based on the various inputs.



You'd think that with all the engineers on board, they'd love to build this just for fun



Later,



Ronnie

 

[RustyJC]

Re: Right on.

Originally posted by moparguy

You'd think that with all the engineers on board, they'd love to build this just for fun

Only if I could start from scratch with my own flowbench and filter samples!



Rusty

 

[Alan Reagan]

To answer your question, here is a pressure conversion chart:

1 Inch of Water Column . 0360 Pounds/sq. Inch

1 Pound per Square Inch 27. 7612 Inches of Water



The RPM to CFM is actually a pretty simple calculation. The engine takes in 5. 9 liters of air every two revolutions, no matter what the pressure. How many pounds of air is that? That's the problem. We are compressing more air into the same volume. So now we have to think of the weight of the air we are putting in versus the volume in cfm. That answer depends on the boost pressure and temperature of the air. But the volume is always 5. 9 liters every two revolutions of the engine. Right? I'm thinking out loud here.

 

[RustyJC]

Originally posted by Alan Reagan

But the volume is always 5. 9 liters every two revolutions of the engine. Right? I'm thinking out loud here.

Alan,



It's a little more complicated than that. Yes, the swept volume is 5. 9 liters every 2 revolutions, but the volumetric efficiency of the engine, valve timing (e. g. , some intake charge is lost back into the intake on the compression stroke before the intake valves completely close) and a number of other factors. Air also flows through the engine without being "trapped" in the combustion chamber during valve overlap - this can be a significant volume!



On an engine test bed, we use a flow nozzle at the turbocharger inlet to measure actual airflow through the engine at a given RPM. Theoretical air would be the 5. 9L every 2 revolutions you cite. Actual air would be flow nozzle measurement (everything corrected back to standard day conditions, of course. ) On a turbocharged low emissions (CleanBurn) 2-cycle engine, we see engines running actual airflow rates of 220% or more of theoretical airflow - standing at the intake filter and exhaust stack outside the building, these engines understandably sound more like gas turbines!



The short answer to your question - if someone is really interested in how much inlet airflow is required for these engines, they need to put a flow nozzle on the turbo inlet during a well-instrumented series of dyno runs.



Rusty

 

[moparguy]

Flow meter for the TDC

OK, here's how you do this on the cheap. First, gotta have a dyno in town, then get to know the guy that test/proves the local gas companys commercial and large industrial gas meters. He's got all the equiptment on board his truck or van to test meters that flow a heck of a lot more gas than our little motors are ever gonna be capable of flowing. Just need to tie the truck to the dyno, sweet talk the measurement tech into hooking up his test equiptment to the boost side of the turbo, and crank it up.



A potential deal killer is that some gas utilities and pipelines have started taking meters out of service at a predetermined time and installing new ones, or testing and rehabing in the shop and reinstalling, no longer field testing.



If the local gas company dosen't have this ability, look on the pipeline side, the company that transports gas to the LDC.



If we only had a dyno in our little town, I could get my old large meter tech to do this at no charge. But, alas, we don't.

 

[tgbol]

May be he could run along side of your truck while pulling that hill outside of town

 

[RustyJC]

Flow Nozzle for Airflow Measurement

Actually, the flow nozzle goes on the inlet side of the turbo. It's an ASME-calibrated venturi or bellmouth with pressure taps strategically located around a specified location on the periphery of its throat. Measured inlet depression can be correlated to flow.



Rusty

 

[Alan Reagan]

RustyJC, Thanks. I needed the volumetric flow number converted from liters to cubic inches to do a spreadsheet. I have completed a spreadsheet now and will be glad to mail it to anyone who wants to take a look at the amount of air being moved. It will only give you two answers at this time... ... The total weight of the air moved in one minute and the conversion (I used . 075 lbs per cubic foot) to volume of air moved in one minute, adjusted to temperature and pressure. This is going to be ballpark only because there are some parameters I don't have such as the intercooler efficiency and turbo efficiency. But it should get you close. Email if you want to try it. The only entries that need to be made are Engine rpm, boost pressure and outside air temperature. The cells are not locked at this time so don't change anything not in red or you could really muss up something.



areagan@msosavannah. uscg. mil